Dark Matter is one of the greatest mysteries facing physicists today. Scientists theorize that most of the matter in the Universe is caused by the invisible mass. There are still many unanswered questions about it. How do we detect it? We have learned a few things about it over time.
According to astrophysicists, Dark Matter played a vital role in the formation of the galaxies and is responsible for keeping them bound. The international team of astronomer found no evidence of Dark Matter when they observed the ultra-diffuse galaxy AGC 114905. If these observations are correct, this discovery could force scientists to reexamine their models of the Universe.
The research team was led by researchers from the Kapteyn Astronomical Institute at the University of Groningen. They were joined by astronomer and cosmologist from other universities. Their research findings will be published in the monthly Notices of the Royal Astronomical Society.
The team explained in a previous study that the road to this discovery began when they observed six galaxies that appeared to have little or no dark. The prevailing theories about dark matter state that all galaxies could not exist without dark matter.
Pia and his colleagues were instructed to use the Very Large array in New Mexico to conduct an observation campaign of one galaxy in particular. AGC 114905 is a gas-rich, ultra-diffuse dwarf galaxy located in the constellation Pisces. Despite being comparable in size, this is a low luminosity galaxy with far fewer stars than ours.
The team collected data on the rotation of gas in AGC 114905 for 40 hours over the course of July and October 2020. The influence of dark matter is shown in a graph that shows the distance of the gas from the center of the galaxy and the speed of it. The motion of the gas in AGC 114905 could be explained by the presence of normal matter alone.
As Pia explained in a recent Royal Astronomical Society press release:
This is what we thought and hoped for, and it confirms our previous measurements. The problem is that the theory predicts dark matter in AGC 114905, but our observations say there isn't. The difference between theory and observation is getting bigger.
Simulation of gas and dark matter. The Illustris Collaboration is a credit.
There are several possible explanations for the lack of dark matter according to Pia and his colleagues. AGC 114905 may have been stripped of its dark matter by interacting with other large galaxies. They adjusted the parameters of the Lamba-Cold Dark Matter cosmological model and alternate theories to get the values they were looking for. Pia explained that none of it worked.
There are no. Extreme parameters would have to be introduced in the so called cold dark matter model in order to be considered in the most reputed galaxy formation framework. We can't reproduce the motions of the gas within the galaxy with modifiedNewtonian dynamics.
It was possible that their estimates of the estimated angle at which they were observing the galaxy were off. Tom Oosterloo, a researcher with ASTRON and a co-author on the paper, said that the angle would have to deviate very much from the estimate before there is room for dark matter again.
This is not the first time that astronomer have seen a galaxy with little or no Dark Matter. A team of American and Canadian scientists led by the Sol Goldman Family Professor of Astronomy at Yale discovered an ultra-diffuse galaxy that was devoid of dark matter. The techniques and measurements used by Pia and his colleagues provided more robust results.
The Hubble image shows an ultra-diffuse galaxy that appears to have little or no dark matter. P. van Dokkum is fromYale University.
In the future, Pia and his colleagues will look at another dwarf galaxy in detail. If they find no evidence of Dark Matter again, it will confirm that there are other universes that defy the?CDM model. This could be good news, as it will apply new constraints on Dark Matter. Most of the greatest breakthrough in history happened when experimental results differed from established models.
The most exciting phrase to hear in science is not 'Eureka', but 'That's funny'.
Further reading: MRAS.
